Air-supply connection for carburetors



Oct. 11., 1927.

A. W. ZERATSKY ET AL AIR SUPPLY CONNECTION FOR CARBURETORS Filed Dec. 13. 1920 Ill 1 I I Patented a. 11, 1927.

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AUGUST w. ZERATSKY Ann WILLIAM v.1 xrnnnn, oF'LA cnossn, WISCONSIN.

AIR-SUPPLY CONNECTION FOB CARBUEETCRS.

Application filed December 13, 1920. Serial No. 430,169.

- Our invention relates to improvements in air supply connections for carburetors. More particularly, our invention relates to that form of air supply connection which is adapted to supply warm air to the carburetor, thereby promoting more perfect carburetion.

The object of our invention is to provide a carburetor air supply connection which may be attached to the carburetor in the place of the tube previously used; and

which, when so attached will rapidly absorb heat from the exhaust manifold and distribute this heat in such a inanner that it will be readily absorbed by air.

passing thru the duct thereby promoting a more perfect atomization and mixture of the gasolene and air; and which will therefore by elimination of waste reduce the quant1ty of gasolene' needed to secure proper combustion in the engine cylinder.

- produce a correct mixture.

. Another object of our invention is to providean air supply connectionthrough which the air will enter the carburetor at a substan. tially constant velocity regardless of the structure of the carburetor with which our invention is associated.

In the drawings: Figure 1 1s a side view of an ordinary internal combustion engine wlth my air ad- 'mission means connected" to the carburetor.

Fig. 2. is an axial sectional view expos ing the interior of my improved air supply connection. 1

Like parts are identified by the same reference characters throughout the several views. The engine block 1 is provided with an intake manifold 2, carburetor 3, and exhaust manifold 4.- in the usual manner.

" 'L-shaped tube 10 With a bulbous enlargement the valve.

The improved air supply pipe comprises simply an 11 and end 12 adapted to be inserted into the inlet of the carburetor. An annular flange 13 gauges thedepth of insertion. At its upper end, thewall at the inner side of the tube is cut away and. the outer side 19 of the tube is flattened 'to have a bearing upon the exhaust manifold 4. As will be hereinafter explained, this contact allows the heat of the exhaust to be conducted by the metal walls of the tube to warm its whole length. l/Vithin the tube and just above .bulbous enlargement 11 above referred to,

is a cross arm 20 provided with an aperture 19 within which the stem 21 of valve 22 is adapted to slide axiallyof the tube. At

its upper end, the valve stem is provided with a pin 23 and washer 24 which forms a seating for spring 25,.the other .end of which bears upon the cross arm which supports It will be noted that the valve is materially less in diameterthan the tube within which it is placed. It will also be noted that asthe valve moves downwardly against the pressure of the spring, it moves into the I bulbous enlargement 11, thereby increasing the area of the spacebetween the valve and the wall of the tube.

This open space surrounding the valve is preferably large enough to permit the passage of all the air needed by the engine at low speeds. But when the engine speed becomes greater and the degree of vacuum in the carburetor increases, the air will rush through our improved supply connection with increased speed and its greater impact upon'the valve 22 will cause the valve to open into the enlarged portion 11 of the tube. As soon as the valve moves the space available for the passage of air is greatly increased and the velocity'of theair is of course correspondingly reducedj Thus the air valve 22 tends to keep the velocity of air entering the carburetor constant.

Within the tube adjacent to the end 12 which is inserted in the'carburetonwe provide a series of helical fins or flanges 15' to set up a whirling motion in the air passing through the tube. We have found that by leaving the space 16 open we are able to make the rotative bend in the tube.

At higher engine speeds when a larger amount of 'air must move through the tube a large proportion of the air will be drawn straight through the open space 16. Ihis is true because the velocity of the air does not increase proportionatelyto the volume.

'Itwill be remembered that the valve 22 tends to keep the velocity of air flow .constant regardless of its quantity. If the velocity were increased, the momentum effects which cause the air to follow the outside of the curve in tube 10wor1ld alsobe increased and probably most of the greater volume of air would be engaged by the helical fins and would be given a correspondingly increased whirling velocity. But the valve 22 tends to keep the. velocity substantially constant and the added volume of air instead of being thrown against outside of thecurve in tube 10 will be drawn directlythrou'gh the central opening 16 where it will-not be engaged by the helical fins 15.

Our improved air intake vtubemay be made ofany desired material, but it is preferable to make the tube. of aluminum because of the high heat conductivity of that metal. It will be noted that the flattened upper portion of the tube which bears upon the exhaust manifold is designed to take heat from the manifold and if the tube is made of aluminum, the whole length of its walls will be heated by the heat thus obtained. Air passing-through the tube will be warmed by the hot walls, The helical flanges adjacent to the carburetor inlet are adapted to impart to the air such heat as still remains unabsorbed thereby. Theseflanges are purposely made very thin to comprise fins for the purpose of promoting deliver of heat to air traversing the device.

YWJGII our improved air inlet is in use, its operation is as follows. The suction produced in the intake manifold 2 of the engine I by the movement of the pistons within the cylinder block 1 draws air through the earburetor 3 and through our improved air inlet tube 10. This air taken from the vicinity of the exhaust manifold 4 has already had its initial chillgremoved so that it enters the tube slightly warm. The aluminum walls of the tube conduct heat rapidly from the exhaust manifold and the air entering the tube rapidly absorbs theheat of the 'walls especially just before the air reaches the carburetor when it passes between the thin helical fianges or fins 15. These fins, besides giving off heat to the air, impart to it a narilv circular in cross section so that the whirling motion imparted to the air by the helical flanges 15 will persist after the air enters the carburetor and will cause the air to pass the jets at a much greater velocity than it would haveha-d if it had followed an axial path through the air supply fitting.

It is well known that the vaporization of a liquid hydrocarbon and carburetion of air thereby can be aided materially by increasing the velocity of the air to which the hydrocarbon is exposed. Our invention makes use of this principle by setting the air to whirling as abovedescribed. It is important, however, that the velocity of airv entering the carburetor shall remain approximately constant so that one adjustment of the carburetor may prove satisfactory for.

all motor speeds. Our valve 22', and the helical thread 15 with its axial opening 16 work together toward this end.

It will be noted that the valveat no time closes the tube but always permits the passage of air. At slow engine speeds, when the degree of vacuum in the carburetor is not great, the valve will not open at all and such air as passes it is forced through the relativelysmall area between the circumference of the valve and the inner side of the tube wall. Theresistance offered to the passage of the air by this relatively small opening will naturally increase somewhat the degree of vacuum within the carburetor so that when our improved inlet tubeis attached to a carburetor, the needle valve will have to be reset to allow for thechanged conditions. Once it is set, however, it will need no further attention because'as the engine speed increases, tending to produce a higher degree of vacuum within the carburetor, the valve will open into the bulbous enlargement '11 and thereby increase the available area for the passage ofair at a rate corresponding to the carburetor requirements so that at all speeds of the engine the air supplied to the carburetor will beunder approximately the same degree of pressure. We are aware that there are carburetors on :the market which accomplish sub'st'anti ally this result, but these carburetors. donor 0})- erate upon the same principle, are ordinarily expensive to construct and consequently sell for high prices and are not standard equipment on the ordinary car.

are equipped and When so applied Will make these carburetors the equal, if not the superior, of the more expensive carburetor.

\Ve claim:

An air inlet fitting adapted to be attached to the inlet ports of internal combustion engine carburetors comprising a metallic tube adapted for contact at its inlet end With a source of'heat, adapted for attachment at its delivery end with the carburetor inlet port, and provided intermediate of its ends With an enlarged portion, a cross arm Within movements, and a set of helical fins pro-f jecting inwardly from the Wall of the tube for a portion'of its radius at a point adjacent the delivery end of the tube.

' A. W. 'ZERATSKY.

WM. V. KIDDER. 

